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breathe easy's Lennox HC16 efficiency test

Hello,

I am considering the Lennox HC16. Back in October 2006 forum member "breath easy" posted some information suggesting that his business was doing testing on it and found that at .3 microns it started at only %85 and then dropped to %79 within one week of use. The test was "temporarily" stopped. I have looked and looked and been unsuccessful in finding out if he had any further results on that test.

It seems like it is nearly impossible to find any information about the efficiency of the filter over an extended period. I have been told by a number of Lennox sources that the media IS NOT CHARGED. If it is not charged, and is purely using physical filtration, it seems that the efficiency would increase with use.

My account is not able to send any PMs so I have to throw the question out. Can someone PLEASE:

1) Direct me to any information regarding if and to what degree the HC16 loses fine particle efficiency as the tests by breathe easy initially seemed to suggest?
2) Tell me if bypass is a problem with the HC16 cabinets as the filter loads (another -OLD- post suggested this may be, but did not provide much more detail)?
3) Provide information regarding how Lennox has a MERV 16 filter that has a "low" pressure drop and supposedly maintains such efficiency and a low drop over an extended period (seems like an impossible/improbable combo)?

I know that with such a knowledgeable base as we have here there could be hundreds of answers based on the knowledge of forum members, but if possible I would like to limit the responses to knowledge based solely on available emperical evidence, personal experience with the HC16, and any testing links etc.

I have an HC16. I can only weigh in on question 2, but I was not impressed with the fact that the filter box was not designed to "seal" in the filter thus creating opportunities for air to bypass the filter. You are literally just sliding the filter into a metal box. The box does have a slot for the filter and the fit is close to being tight, but there is clearly space on the top, and maybe the sides, where air will easily bypass the filter. I ended up buying rubber weatherstipping and put it on top of the filter and then slid the filter in....I used thick enough weatherstripping where there was slight resistance to sliding the filter in. I'm sure its not perfectly sealed now, but is definitely better. Admittedly, adding weatherstripping to a furnace filter is probably over the top and most people wouldn't bother, but there is no point in having and paying for a Merv 16 filter if air can bypass the filter.

I have an HC16. I can only weigh in on question 2, but I was not impressed with the fact that the filter box was not designed to "seal" in the filter thus creating opportunities for air to bypass the filter. You are literally just sliding the filter into a metal box. The box does have a slot for the filter and the fit is close to being tight, but there is clearly space on the top, and maybe the sides, where air will easily bypass the filter. I ended up buying rubber weatherstipping and put it on top of the filter and then slid the filter in....I used thick enough weatherstripping where there was slight resistance to sliding the filter in. I'm sure its not perfectly sealed now, but is definitely better. Admittedly, adding weatherstripping to a furnace filter is probably over the top and most people wouldn't bother, but there is no point in having and paying for a Merv 16 filter if air can bypass the filter.

Thanks for the reply,

That doesn't sound like too big of a deal, and I do agree. There is no point to having and paying for a MERV 16 filter if bypass is likely... I get the impression from others I speak with that the fit is quite tight and presumably that with the door in place and air pressure together, the seal is quite good, but I can't imagine that the weather stripping is a bad thing.

Again, thank you. We'll see if anyone can chime in on the rest. Overall, the HC16 seems like a minimally compromised and very economical step into the higher end.

Sorry for the delay in responding. I will try to answer your question, but it has been a few years since I did some of these tests. The Lennox HC16 is a very efficient filter. The best part is that it uses no electricity to achieve its efficiency and low pressure drop. The biggest drawback is the price. I would think you would pay over $100 for a replacement filter.

The HC16 filter does use electret media. It would not be able to achieve the fine particle removal rates with their pressure drop without it. This means that it will decrease in efficiency on the small particles until the mechanical mechanisms of the dirty filter kick in. I do not know how much of drop this would be.

The fact that the filter is not a tight fit in the filter box is not a big concern. As long as the filter box has a lip the air pressure will force the filter to the air leaving side and provide a reasonably good seal. In any event, you are not going to get enough air bypass to make much of a difference in a household environment.

My favorite recommendation for a homeowner is a commercial 4" filter. You should be able to locate a filter box that will fit this type of filter. You can purchase a commercial 4" MERV 11 filter for less than $15 or you could go to a MERV 13 for less than $25. This thickness will give you plenty of surface area which provides low pressure drop and long life. And the difference in efficiency in a home between a MeRV 11 and the HC16 is negligible. The limitations on the HVAC system in reducing particles such as limited run time, outdoor to indoor particle transfer, interior particle generation sources (mostly people) and insufficient air circulation will negate any increase in efficiency. In other words your indoor particle levels are going to be about the same using anything MERV 11 or above.